Question: Mapiya writes a series of novels. She earned $\$75{,}000$ for the first book, and her cumulative earnings double with each sequel that she writes. Write a function that gives Mapiya's cumulative earnings $E(n)$, in dollars, when she has written $n$ sequels. Do not enter commas in your answer. $E(n)=$
Explanation: For each sequel Mapiya writes, her cumulative earnings are multiplied by a factor of $2$. If we start with the initial value, $\$75{,}000$, and keep multiplying by $2$, this function gives us Mapiya's cumulative earnings when she has written $n$ sequels. $E(n)=75000\cdot 2^n$